Process for treating hydrocarbon oil



. Fatented Apr. 23, 1929.-

UNITED STATES PATENT OFFICE.

JACQUE G. MORRELL, OF CEHICAGO, ILLINOIS, ASSIGNOR To THE UNIVERSAL OIL PROD- UCTS COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF SOUTH DAKOTA.

PROCESS FOR TREATING- HYDBOCABBON OIL.

No Drawing. Application filed August 31, 1922,

This invention relates to improvements in the process for treating hydrocarbon oils, and refers more particularly to a process for the treatment of cracked 'distillates containing sulphur compounds.

Among the objects of the invention are to provide a process by means of which the sulphur content of the oil maybe reduced by the introduction of oils in which the sulphur is more soluble, thus relieving the low boiling point distillates of the objectionable ingreclients.

Cracked distillates such as those recovered in the pressure distillation of hydrocarbon oils often contain an objectionable amount of sulphur, particularly such oils as the distillates recovered from Texas, Mexican or California oils.

ln refining the cracked distillates produced in this manner, the oil may be first thoroughly agitated in the presence of sulphuric acid in the proportion of say 3 to 10 pounds of acid per barrel, for a period of 15 to 20 minutes, more or less. lhe oil after separation from the acidand sludge may be treated with a basic cleansing agent or alkali wash such as caustic soda in the proportion of say 35 gallons of 6-12 degrees Baum per 100 barrels of oil treated. lhe oil may be Water washed at any time during the treatment. The oil after being separated from the basiccleansing agent may be then treated with a plumbite solution containing litharge dissolved in caustic soda, or sodium plumbite, or sodium hydroxide in the proportion of say 5 barrels of 16 to 30 degrees Baum caustic containing from 5 to 30 pounds of litharge for each 100 barrels of oil treated. After the removal of the plumbite solution, the oil may be subjected to an additional cleansing Water wash.

'lhe distillate is then subjected to a steam or steam and fire distillation. For certain cracked distillates, such treatment is suliici'ent :tor desirable results, that is, relieving the oil or the objectionable sulphur ingredients, and refining the oilsuficiently to pass the specification test required for motor fuels, partied larly with regard to the presence of certain types of sulphur compounds. However, with other hydrocarbon containing a hi h percentage of sulphur and other objectional compounds as well as a high percentage of gasoline, dificulty is presented in obtaining a mo- Serial No. 585,549. Renewed September 13, 1926.

tor fuel which will meet the specification requirements with regard to sulphur.

In order to reduce the sulphur content, varlous methods have been devised. Some of these'are comparatively satisfactory, but most of them are objectionable due to the cost and water white distillate of much lower sulphur.

content than the original was obtained, meetmg all specification requirements with re- L gard to sulphur. A pressure distillate containing 56% of gasoline of a certain initial and end point, produced from Mexican gas oil when subjected to the treatment with sodium plumbite, gave a gasoline or motor fuel not meeting the requirements with regard to its sulphur content. After 1 retreating this pressure distillate, distillate with the bottoms or high boiling point products in proportion so that the gasoline consisted of from'40% to 50% of the mixture, and subjecting it to a redistillation, a relatively clear'water white distillate meeting all requirements was obtained. It is thus obvious that the sulphur compounds have a relatively stronger afiinity for the high boiling point oils or bottoms and are more soluble in the heavier ends or high boiling point frac-" tions so that 'by increasing the relative proportions of the bottoms or heavy ends, a more 1 desirable product is obtained with a lower sulphur content. It is important that the higher boiling point fractions or bottoms be obtained from a treated cracked distillate, that is from a distillate which has been subjected to treatment of a plumbite solution or similar refining methods, preceded by the sulphuric acid and Washes previously described. If the higher boiling point fractions or bottoms of an untreated cracked distillate are used, sulphur contamination of the. obtained distillate is more likely. 4

By utilizing this tendency of the higher boiling point oils to absorb the'sulphur compounds from the lower boiling point fractions, different percentages of the low and high boiling point distillates may be mixed in order to procure the necessary or desirable results. A pressure distillate containing 56'% of gasoline produced from Mexican gas oil contained a relatively highv sulphur content, but when mixed with distillate bottoms of a relatively higher boiling point and obtained from the initial distillation of the cracked distillate, a water white product of low sulphur content was obtained by distillation, the greater part of the sulphur transferring to the higher boiling point products.

In addition to using the bottoms procured from the initial vdistillation and combining them with the distillate from which it is desired to extract the sulphur compounds, bottoms such as those collected from previous distillates may be used.

It may be noted that the treatment of the bottoms as herein referred to does not always imply the necessity of two successive distillations in order to first procure bottoms of high boiling" point oils to be later added to the distillate treated, but once a stock of high boiling point oils is obtained, this may sometimes be used in successive treatments of the pressure distillate containing high sulphur compounds, thus making the treatment more economical.

I claim as my invention:

1. A process for refining hydrocarbonoil comprisingremoving a portion of the sulphur content by subjecting the oil to treatment with plumbite solution, removing said solution and distilling the oil, combining the recovered distillate with refined residual oil from a previous distillation toform a mixture in which the residual oil is in excess of and subjecting the mixture to a redistillation. r

2. A process for refining cracked distillate 3. A process for refining hydrocarbon oil comprising reducing its sulphur content by treatment with a plumbite solution, distilling thetreated oil, and subjecting the recovered distillate in admixture with the residue obtained'in the initial distillation to a redistillation.'

4. A process for refining hydrocarbon oil comprising removing a portion of the sulphur content by treatment with a plumbite solution, subjecting the treated oil to a distilling action, mixing a minor portion of the distillate obtained with a major portion of unvaporized residue from the initial distillation, and subjecting the mixture to further distillation.

5. A processfor refining hydrocarbon oil comprising subjecting the oil to the action of successive acid and alkali washes, and to treatment with a plumbite solution, subjecting the treated oil to a distilling action, mixing a minor portion of the distillate obtained with a major portion of higher boiling point oils and subjecting the mixture to further distillation.

6. A process for refining hydrocarbon oil comprising subjecting the oil to the action of successive sulphuric acid, water and alkali washes, treating the oil with a plumbite solution and then subjecting the treated oil we distilling action, mixing minor percentages of the distillate with major percentages of relatively high boiling point residual oil, and subjecting the mixture to further distillation; I

JACQUE C. MORE-ELL. 

